The number one reason is to protect personal assets from liability associated with business activities. E.g. if his wiid-workign business makes a large piece of furniture for a client, and the client's kids are rough-housing and cause it to fall over on one of them resulting in severe injury, they will be contractually limited to suing the LLC -- they may be able to wipe out the LLC, but will not be able to get to the family's personal assets.
Personally, I'm not arguing with you that these people are desperately poor and deserve to have the taxpayers pick up the tab for their medical bills. But I think it's important to check your facts carefully before making accusations, because your whole argument loses credibility when chunks of it can quickly be proven false. It's very easy for political opponents to distract people from the main focus of your argument, when you give them piles of ammo with which to assail your credibility.
Was there anything I posted on this topic that was quickly proven false? Or slowly proven false? Or false at all?